Balls, of which there are a wide variety, are a classic play toy which in many of its variations are used in athletics. Most balls are spherical so that the ball can be controlled and the bounce or rebound can be predicted. There are both high rebound balls, of high durometer elastomeric plastic of cured urethane, polybutadiene and other polymer compositions, and soft, low rebound balls of sponge rubber or open or closed cell plastic. To Applicant's knowledge, while small 1-2" oval-shaped elastomeric balls are available, there are no properly-sized exercise or athletic balls that are egg-shaped due to the user's inability to control the ball and/or predict its rebound.
A number of toys have been proposed using egg-shaped balls, among them, Gehlen U.S. Pat. No. 3,195,267, which is directed to a V-shaped trough having legs at one end to form an incline down which is rolled an egg or "synthetic", non-bounceable egg. The synthetic egg is a shell containing heavy grease and having a smaller round ball or heavy weight embedded in the grease to provide a center of gravity.
Stroud U.S. Pat. No. 3,712,627 shows an egg-shaped elastomeric ball having a hollow space at the large end. This ball is specifically engineered to have a center of gravity space between the center of the major axis and the longitudinal midpoint. One end is hemispherical and the other parabolic with essentially no transition zone therebetween.
Craig U.S. Pat. No. 4,003,573 shows an irregularly shaped ball, generally oval in shape, having both ridges and grooves between the ridges to provide erratic and unpredictable bounces. Fleischer U.S. Pat. No. 4,219,959 is a toy egg composed of two intertwined helically cut shells of plastic. Brewer U.S. Pat. No. 3,885,795 is directed to an egg-shaped golf ball with a dimpled surface for a miniature golf game.
None of these balls have been taught to be thrown except for Craig U.S. Pat. No. 4,003,573 and Fleischer U.S. Pat. No. 4,219,959. The former clearly indicates that the ball is not controllable because of the ridges and grooves. It derives its amusement effect from the unpredictability of the rebound.
All of these balls eliminate the skill factor, which is one of the greatest satisfactions in amusement, athletic and entertainment devices. Accordingly, there is a need for an improved ball which due to its non-round shape provides a high degree of control challenge.